Mike Dolt Enterprises
Mike Dolt Enterprises
User: paulgarett, Location: San Rafael, CA
Asked on: Monday, May 2, 2011 at 10:20 pm EDT
Answered on: Tuesday, May 14, 2024 at 4:53 am EDT
Question: Some interesting load calculation questions. Thanks for your help.Paul.1. How should motors for a residential workshop, be included in the main service load calculations?2. How should the 1500 VA small-appliance load, be included for a workshop and an art studio? The workshop and the art studio both have bathrooms and a sink counter area.3. How should a 240 Volt, 50 amp hot tub be included in the main service load calculations?4. The largest load of an A/C or a heater is included, the smaller omitted. Would a hot-tub be a part of this rule?5. How should a portable, yet somewhat permanent, space-heater load be included in the main service load calculations?6. If the space heater is the only means of heating the art studio, would it be included as a small appliance, the heating load, or the general lighting load.
1. Residential Workshop Motor Load Method 1 (Standard)
Include 100% of the motor load (nameplate rating) in the load calculations.
Method 2 (Optional)
Use a diversity factor of 0.75 for multiple motors with a combined horsepower greater than 3. This reduces the load by 25%.
2. Small-Appliance Load for Workshop and Art Studio Include the full 1500 VA small-appliance load for each space. Additionally, include 100 VA per linear foot of countertop for the sink counter area.3. Hot Tub Load Include the hot tub's connected load (50 amps x 240 volts = 12 kW) at its full rated value. Consider using a separate branch circuit for the hot tub.4. Largest Load Rule for A/C and Heater This rule does not apply to hot tubs. For hot tubs, include the full connected load regardless of whether it is the largest load.5. Portable Space Heater Load Treat portable space heaters that are likely to be used frequently as part of the general lighting load. For heaters that may be used infrequently, consider using an alternative calculation method (e.g., multiplying the heater's wattage by an estimated duration of use per day).6. Space Heater Load for Art Studio Since the space heater is the only means of heating the art studio, it should be included as the heating load. Do not include it as a small appliance or general lighting load. Flag for review